"All this stuff coming from Trump, you know, American workers are getting paid too much? Where the hell does he live?" Biden said, according to a White House pool report. "Well, I know where he lives. But I'm serious, think about it."

During a November GOP debate, Trump suggested that American wages are already "too high." He has since altered his position and become more open to the idea of raising the minimum wage.

American workers are "three times as productive as they are in Asia, we're in a situation where we have the greatest research universities in the world, the most agile venture capitalists in the world," Biden said Wednesday. "This is time for the United States just to step up and step in. And I think there are so many opportunities, and I feel confident about this year."

Biden asked rhetorically if anyone present would rather change places with China or the European Union.

"I mean come on, man," Biden said. "I've been saying this for eight years. [And people who say,] 'Well, you know I heard about how China's going to eat our lunch.' Come on, give me a break. Give me a break. 'The EU's going to dominate us.' You want to make any bets on that one? We want EU, we want China, we want to do better."

Biden also said Wednesday that he believes Democrats will be unified for a general-election matchup with Trump, despite increasingly heated rhetoric between frontrunner Hillary Clinton and Sen. Bernie Sanders.

"I'm confident that Bernie will be supportive if Hillary wins, which the numbers indicate will happen. So I'm not worried," Biden said. "There's no fundamental split in the Democratic Party."